Solar distilling apparatus



April 9, 1946. w. R. P. DELANQ SOLAR DISTILLING 'APPARATUS Filed Nov. 2,1943 IN VEN TOR. WILLI/)M RE DEM/V0 Tfam Patented Apr. 9, 1946 UNITEDSTATES PA'rEN'r OFFICE N Gallowhur Chemical Corporation, New York,

N. Y., a corporation of Vermont Application November l Claims.

This invention relates in general to distillation and in particular to aprocess of making an apparatus for distilling liquids, in particular-sea water, and to correlated improvements designed to render such anapparatus collapsible and port-4 able.

The need of a simple and convenient method of distilling impure water,such as sea water, for the .production of fresh water for drinking andthe like has long been recognized, but this need becomes increasinglylimportant during times of War when the destruction of ships andairplanes at sea forces the crews to take to lifeboats, rafts andfloats. Accordingly, any apparatus for distilling sea water to producefresh water for drinking on lifesaving craft must meet, inter alia, thefollowing stringent requirements:

1. The device must have a relatively low weight per unit of capacity.

2. The device must be compact and occupy a small space when not in use.

3. The device must be resistant to corrosion by sun, air, water and theaction of the salts contained in sea water.

4. The device should be easy to erect and simple to operate.

5. The apparatus should be capable of being fabricated without the useof critical or scarcewar material.

6. The device should operate upon a source of cheap, plentiful fuelwithout the use of an open flame which would create a lire hazard.

'7. The fresh water produced should be free of salts, of harmfulbacteria and should be substantially odorless and tasteless.

Accordingly, it is the general object of the present invention toprovide an apparatus for the distillation of liquids, in particular seawater. which will satisfy the objects above described an meet thespecifications recited. f

It is a further object of the invention to provide a simple means fordistilling sea water which is adapted for use on small lifesaving craft.Y

It is a further object to provide an apparatus for distilling sea waterwhich will be collapsible, compact and light in Weight, so that it canbe carried in airplanes and installed as regular equipment in smalllifesaving craft.

It is a specific object of the invention to provide a process forproducing a collapsible, port able distillation apparatus fromessentially a single piece of sheet material in a simple, rapid andinexpensive manner.

Other objects of the invention will in part be obvious and will in partappear hereinafter.

2, 1943, Serial No. 508,677

According to the present invention there is provided a process formaking a distillation apparatusby foldingvan elongated piece ofliquid-impermeable material approximately in the center so as to bringthe ends together and sealing the folded material transversely so as todivide the interior into essentially three compartments with the centralcompartment having the greatest length, a layer of liquid absorbentmaterial being sealed in the seams dividing said compartments from eachother and being adhered to the inner surface of one wall of the middlecompartment, whereby the rst compartment provides a reservoir for theliquid to be distilled, the middle compartment provides a space in whichthe liquid is distilled, and the bottom compartment provides a reservoirfor the distillate.4 Optionally shaping or reinforcing members may beinserted both transversely and lengthwise of one or more of thecompartments to maintain the shape and the spacing of the walls of oneor more of the compartments.

When the apparatus is to be used for distillation by solar radiation,the sheet material is transmaterial is opaque, there may be cut in thefront wall of the middle compartment a window which is covered with atransparent liquid-impermeable sheet material.

The invention laccordingly comprises the several steps and relation ofone or more of such steps with respect to each of the others, and thearticle possessing the features, properties, and the relation ofelements, which are exemplified in the followed detailed disclosure, andthescope of the invention will be indicated in the claims.

For a more complete understanding of the nature and the objects of theinvention, reference should be had to the accompanying drawing in which:

Fig. 1 is a top plane view of a template or pattern by which the basicsheet material isftfo `be cut and folded;

Fig. 2 is a side elevation partly in section of the article produced by'folding the sheet material shown in Fig. 1 along the lines indicated;

Fig. 3 is a perspective view of one embodiment of the distillationapparatus of the present invention, and

Fig. 4 is a perspective view of the apparatus of Fig. 3 in a folded andpackaged condition.

It is to be understood that the apparatus comprises three main velementsand several optional but desirable elements. The chief elements are 55(1) the transparent window, (2) lthe layer of parent to sunlight, oralternatively, if thesheet the outer edges and along fold line 2Iabsorbent material, and (3) the shaping means. i. e., the means by whichthe article is given form and rigidity and proper disposition of theabsorbent layer with respect to the window. Each of these elements willbe described by reference to a particular embodiment, after which ageneral discussion of the elements will be given. Itis to be understoodthat the invention is not limited to the specic embodiment described indetail hereinafter.

Referring to Fig. 1 the apparatus is produced by taking a single sheetof liquid-impermeable material and cutting therefrom an elongated pieceas shown in Fig. 1, the piece being folded transversely andlongitudinally along the broken lines as indicated.

Referring now to Fig. 2 it will be apparent that the transverse foldsproduce the following sections: The folds I and II provide thetransverse strip A which forms the transverse sleeve 24. The fold I2provides the walll section B of the upper liquid compartment 25. Thefold I3 provides the back wall C of the upper liquid compartment 25. Thefold I4 defines the lower edge Aof the middle or distilling compartment26 and provides the back wall D thereof. Fold lines I5 and I6 dene thedouble reverse fold E which provides a small channel 21 at the base ofthe middle compartment 26. The fold line I1 defines the back wall F ofthe lower liquid compartment 28. 'I'he fold line I8 denes the front wallG of the lower liquid compartment 28 and thev space between fold I8 andfold I9 defines the front wall H of the middle compartment 26,"while thefold I9 coincides with the fold lines II and I3. The folded material isstitched along the various fold lines as indicated by the letter S inFig. 2.

Before the folding and sewing of the sheet material, there is adhesivelyunited to the inner surface of the wall H a strip of absorbent materialsuch as a textile tape 29- which is transversely disposed in a V-shapewith-a fold 30 extending through the stitching of the fold line I6. As amatter of fact, it is preferable not to stitch the fold I8 across thearea occupied bythe fold 30 by the tape 29. The function of this-tapewill be explained later.

The lower transverse pocket 3l may be, formed either by making a doublereverse foldl in the sheet material at the fold line I8, or by attachinga separate strip of material 32 and sewing it transversely over the foldline I8 as shown in Fig. 2. Before the stitching of the materialtransversely along the fold lines I3, I4, I5, I6, I1 and I8, there isdisposed and preferably adhesively united to the inner surface of thewall D a layer 36 of absorbent material having the width and breadthshown in Fig. '1, its length being sumcient so that the upper endextends into the liquid compartment 25 and its lower end extends intothe channel 21.

The longitudinal side seams are also made by sewing together theoverlapping layers of the sheet material. On one or both sides, however,

- the marginal longitudinal edges are cut along the foldV lines I4 andI6 to sever the material to the fold lines 2I or 2|', as/the case maybe, and thus provide a small' section E, thel edges 22 of which arebrought together and stitched to form the tubular extension or spout 23.The marginal areas I, J, I and J are stitched both at to form thelongitudinal sleeves 33 and 33.

When the apparatus is to be used .for'distillation by solar radiation,either the sheet mate- :,seaasa rial must 'be transparent or a windowshould be cut in the Wall H, for example as shown along the broken lines84 in Fig. 1, and the opening covered with a liquid-impermeable materialforming a transparent window. It is to be understood that when the basesheet material is inherently heat-scalable or is coated with aheat-sealable composition. all or part of the seams required in themanufacture of the article and referred to above as being stitched may,0n the contrary, be formed by heat-sealing under heat and pressure withor without the aid of an organic solvent to soften the thermoplasticmaterial; or alternatively, all or part of the seams may be formed bythe use of'a suitable adhesive.

By way of illustration'but not by way of limitation, there will be showna simple means of using battens to provide a proper. rigidity anddisposition of the Walls in the apparatus. Referring to Fig. 3 there isdisposed in the pockets 24 and 3|, transverse battens 40 of rigidmaterial, while there is disposed in the longitudinal sleeves 33 and 33'battens 4I. The battens 40 pass through holes positioned adjacent th'eends of the battens 4I. If desired, the ends of the battens 40 may berotatable and provided with threads which engage threads within theholes 42' of the battens 4I, so that by rotating the ends of the battens40 th'e transparent window 35 may be stretched transversely, while byrotating the ends of the rods 40 in the reverse direction, the battens40 will be shortened, thus facilitating the removal of the battens 4Ifrom the sleeves 33.

In the upper compartment 26 there is provided a slit 43 through which'liquid may be introduced into the compartment 25. The liquid thusintroduced will Wet the upper end of the absorbent layer 36 andgradually saturate this layer with the liquid to be distilled. Upondisposing the apparatus so that the wall H or window 35 is parallel tothe suns rays, the absorbent layer will be heated and the liquid thereinwill be vaporized. The vapor will condense on the inner surface of thewall H or window 35 and drain downward and along the tape 29 and dripinto the compartment 28, from which it may be drawn 0E through theoutlet tube 43 which' is provided with a pinch clamp 44. Any excessliquid in the layer 36 will drain into the channel 21 and run outthrough the spout 23.

When it is desired to compact or fold the apparatus, the battens 4I areremoved and placed transverse the apparatus which is then rolled uponitself to give th'e compact body shown in Fig. 4. 'I'he compactedapparatus may then be packed in a container 45 which may be providedwith a cap 46. Thus the apparatus can be folded into asmall compact unitfor carrying for shipment and for storage in a lifeboat or airplane.

The transparent window The sheet of transparent material shown in theapparatus of Fig. l should be a flexible but form-retaining sheet of anysuitable transparent material, such', for example, as a cellulose ester,a cellulose ether, or a synthetic resin. Preferably, there is employedfor this sheet material a transparent plastic which is permeable tovisible and infrared radiation such, for example, as ce1- lulose acetateand cellulose aceto-butyrate. It is obviousl that evaporation can takeplace from both the front and rear surfaces of the absorbent layer.

Since the transparent window divides the warm moist air 0f the interiorfrom th'e cool dry air on the outside or mewindow, there win be normallya tendency of the window to become fogged by the condensation of`droplets of water on the inner surface. Such droplets diffuse the lightand decrease the radiation absorbed by the layer of absorbent material`Accordingly, it is desirableto retard or prevent fogging of thetransparent window. This, may be accomplished by forming the window oftransparent material combined on one or both sides with a layer ofwater-absorbent, that is hydrophilic material, which absorbs thecondensed water and prevents it from remaining as individual droplets,as'desscribed in my co-pending U.' S. applications Serial Nos. 500,882filed September2, 1943and 501,219 illed September 4, 1943. L I

The absorbent layer For the layer of absorbent material, there'may beemployed a layer of a viscose sponge, a pile fabric, a layer ofinter-felted fibres, such, for example, as textile felt or a soft,porous paper which| has been sized with a water-insoluble substancesuch, for example, as casein, a resinror a cellulose ester which doesnot disintegrate when wet. Since the layer should be capable of beingwashed and wrung out, itis preferably formed o f a material having asuilicient tensile strength for this purpose, that is, a textile fabricor felt, or sponge.

The absorbent layer` is preferably colored black to render it moreh'eat-absorbent and this may be done by dyeing or pigmenting theabsorbent material with a suitable black dye or carbon black. 'RJ insurethat the fresh water is' free of harmful bacteria, the absorbent layeris advantageously rendered bacteriostatic or fungistatc and germicidalby combining it, e. g. by impregnation or coating, with a suitablewater-insoluble germicide such, for example, as a phenylmercurycompound, finely divided ionized heavy metals, such as silver, copper orgold, or by means of an organic` subi stantially water-insolublegermicide such, Afor example, as copperflnaph'thenates, phenyl mercurychloride, phenyl mercury hydroxy quinoline, anddichlorodihydroxymethane. y

The shaping means When the vsheet materialv is sufficiently self rialunited to the back wall D of the compartment 26 as described and'claimedin the copending application Serial No. 500,550'led August 30, 1943, or(b) by theA use of stretching battens as disclosed in my parentco-pending application Serial No. 465,366 filed November 12, 1942, or(c) by inating the chamber 26 with air or gas as Since most orga'nicplastic materials contain residual volatile solvents or volatileplasticizers, they tend to undergo changes in dimension when subjectedto such temperatures as are generated by the sun's rays. Therefore, inthe now preferred embodiment, the sheet materials, before or after beingincorporated in the device, are preheated to shrink them, as describedin my co-I pending U. S'. applications Serial Nos. 500,882 led September2, 1943, and 501,219 filed September 4. 1943.

This application is a continuation-impart of my co-pending applicationSerial No. 465,366 filed November 12, 1942, and Serial No.501,219'led,September 4, 1943.

I claim:

A s 1. Solar distillation apparatus comprising an f n enclosure formedof a single rectangular sheet of transparent water resistant materialfolded upon itself substantially midwaly of its length and sealed at itsedges to form an enclosure, the resulting layers being incompletelysecured together along transversely extending lines to form threesuperimposed communicating chambers, the uppermost chamber beingrelatively small and having means communicating therewith to supplytheuppermost chamber, with liquid to be,distilled, the lowverxnostchamber having means communicating therewith for discharging distillatetherefrom, the central chamber having absorbent material thereinextending into the uppermost chamber past the transversely extendingconnection which vforms the latter chamber to conduct liquid into saidcentral chamber'and distribute the same for exposure to solar radiation,said absorbent mate- -rial being spaced from one wall of said centralchamber to permit condensate to collect on said wall and iiow downwardthereover to the lower- 'most chamber.

2. Solar distillation apparatus comprising an enclosure formed of asingle rectangular sheet of transparent water resistant material foldedupon itself substantially midway of its length and sealed at its edgesto form an enclosure, the resulting layers being incompletely securedtogether along transversely extending lines to form three superimposedcommunicating chambers, the uppermost chamberbeing relatively small andhav-v ing means communicating therewith to supply the uppermost chamberwith liquid -to be distilled, the

lowermost chamber having means communicating described and claimed in myco-pending U. S.

application Serial No. 501,219 filed September 4, 1943.

All other sheet materials used in the apparatus may be formed ofanyflexible non-porous sheet material such, for example, as an organicplastic,

therewith for discharging distillate therefrom, the central chamberhaving absorbent material therein extending into the uppermost chamberpast the transversely extending connection which forms the latterchamber to conduct liquid into said central chamber and distribute thesame for exposure to solar radiation, said absorbent material beingspaced from one wall of said central chamber to permit condensate tocollect on said wall and flow downward thereover to the lowermostchamber,

and means for securing said absorbent material to the opposite wall ofsaid central chamber.

3. Solar distillation apparatus comprising an enclosure formed of asingle rectangular sheet of transparent water resistant material foldedupon itself substantially midway of its length and sealed at its edgesto form an enclosure, the resulting layers being incompletely securedtogether along transversely extending lines to form three superimposedcommunicating chambers, the uppermost chamber being relatively small andhaving means communicating therewith to supply the uppermost chamberwith liquid to be distilled, the lowermost means communicating centralchamber having absorbent material therein extending into the uppermostchamber past the transversely extending connection which forms thelatter chamber to conduct liquid into said central chamber anddistribute the same for exposure to solar radiation, said absorbentmaterial being spaced from one wall of said central chamber to permitcondensate to collect on said wall and ow downward thereover to thelowermost chamber, means for securing said absorbent material to theopposite wall of said central chamber, the material forming saidopposite wall being formed with a reversely folded portion 1ocated abovesaid lowermost chamber and receiving the lower edge of the absorbentmaterial, and means communicating with the reversely folded portion fordischarging excess liquid supplied to the aabsorbent material anddraining from the o Y 2,398,292 therewith for discharging distillatetherefrom. the

ing means for holding said central chamber extended.

5. Solar distillation apparatus comprising an enclosure formed of asingle rectangular sheet of transparent water resistant material foldedupon itself substantially midway of its length and sealed at its edgesto form an enclosure, the resulting layers being incomplet'ely securedtogether along transversely extending lines to form three superimposedcommunicating chambers, the uppermost chamber being relatively small andhaving means communicating therewith to supply the uppermost chamberwith liquid to be distilled. the lowermost chamber having meanscommunicating therewith for discharging distillate therefrom, thecentral chamber having absorbent material therein arranged toreceiveliquld from the upper chamber andto distribute and retain theliquid in position to be exposed to solar radiation, said absorbentmaterial being spaced from one wall of said central-chamber to permitcondensate to collect on said wall and ow downward thereover to thelowermost chamber.

WILLIAM R. P. DELANo.

